The invention relates to a tube pump for the conveyance of liquid or viscous media.
Tube pumps are generally known and exhibit a pump head on which at least two pump rollers are arranged which can be brought into engagement in succsession with a turbo (pump hose) wherein the medium to be conveyed is contained, in such a way that the medium is transported by tight squeezing of the tube. As a consequence, tube pumps have the advantage that the conveyed medium comes exclusively into contact with the pump hose which latter can be exchanged in a relatively simple manner.
Thus, tube pumps are suited, for example, for transporting sterile solutions. It is merely necessary for this purpose to utilize sterilized pump tubes and/or tube kits which can be designed as disposable articles as well as in the form of repeatedly usable kits.
In the conventional tube pumps, the pump head is normally designed as a swivel plate, the individually rotatable rollers being arranged along the circumference thereof. The rollers squeeze the pump tube tightly and thus convey the liquid present therein according to the peristaltic pump principle.
A distinction is made between two subordinate kinds in tube pumps of this type:
The first subgroup exhibits a fixed tube bed against which the tube is pressed by the rollers which latter can be mounted either resiliently or fixedly. Normally, the rollers exert pressure radially toward the outside; however, there are also special models wherein the tube bed is located within the roller rim. For purposes of insertion, the tube must either be urged or pulled in between the rollers and the tube abutment by manually twisting the pump head, for example; or the tube bed must be removable or displaceable.
In the second subgroup, the pump tube is tensioned against the rollers. In order to obtain adequate occlusion (i.e. tight squeezing of the tube in the region of the rollers), usually at most three rollers can be utilized in such a structure. Additionally, due to the tensioning step, the tube cross section is reduced and/or flattened so that the maximally feasible throughflow efficiency is reduced.
Both subordinate types have the drawback that insertion of the pump tube is either very troublesome and requires great manual skill, or the tube bed must be removed or displaced in order to insert the tube.